Abstract: This automatic telephone line fault locator comprises a portable box-type structure which comprises an interface section including switches and having input terminals for connection to a line being controlled, a voltage and current measuring section electrically connected to the interface section for selectively measuring currents and voltages of suitable portions of the line being controlled, a control unit including a logic-arithmetic and control section coupled to the interface section and the measuring section for controlling the position of the switches and receiving the measured current and voltage values and calculating therefrom the position of any fault on the line.